a) Field of the Invention
The present invention relates to an anti-jam knife device for a paper shredder, and more particularly to a paper shredder, a blade shaft of which is transfixed with a circular parting wheel closely adjacent to a guide-parting plate, with an outer diameter of the parting wheel being higher than a parting knife-edge at a bottom of a notch of the guide-parting plate, such that paper jams can be prevented while shredding the paper.
b) Description of the Prior Art
Cutting wheels of an ordinary paper shredder are constituted by two cylindrical rotary shredding wheels that rotate in opposite directions (clockwise and counterclockwise); whereas, the cylindrical rotary shredding wheel is assembled by a blade shaft and a plurality of shredding blades that are sheathed on the blade shaft and are separated with each other with a gasket. The two cylindrical rotary shredding wheels are placed side by side, and installed parallel on a blade rack, with every blade, which is aligned on one of the two cylindrical cutting wheels, being intersected with each other to form a plurality of cut-openings. As the rotary shredding wheels should bear with certain pressure when shredding paper sheets that are fed in, a certain requirement for intensity and rigidity of the two cutting wheels is available. Otherwise, when the paper shredder operates in high speed to shred the paper sheets, the two cylindrical rotary shredding wheels will be pushed open against each other if too many paper sheets are rolled into the cut-openings of the rotary shredding wheels. This push-open phenomenon will not only enable the shredding blades of the cylindrical rotary shredding wheels to be fractured very easily, such that a shredding effect of the paper shredder will be affected; but also will affect a normal operation of the paper shredder in a severe condition. On the other hand, during the paper shredding operation, an operator feeds the paper sheets that need to be shredded into the paper shredder from a strip-shape aperture on a face cover of the paper shredder, allowing the cutting wheels that are operating in high speed inside the paper shredder to cut and smash the paper sheets that have been fed in. However, the strip-shape aperture on the face cover of the paper shredder will be pushed open when too many paper sheets are fed in; and if the strip-shape aperture is pushed open excessively, a more significant safety concern will be formed and a safety regulation cannot be satisfied either. Accordingly, the normal operation of the paper shredder will all be affected when the shredding wheels are pushed open, and the strip-shape aperture on the face cover of the paper shredder is widely pushed open.